屋顶绿化基质雨水滞蓄效果影响因素研究

摘要

The water storage capacity of saturated green roof substrates is defined as the maximum water content,which is important for evaluating the effect of rainfall detention.In this research,ceramics particles,peat,and coal cinder were selected to design the substrate of green roof by adjusting the combinations and mixing proportions.The influences of substrate thickness,rainfall intensity,and substrate type on the effect of rainwater detention were investigated through artificial rainfall experiments.Results suggest that thickness and rainfall intensity have no effect on the maximum water content in the presence of the same substrate.But with the increase of substrate thickness,the total capacity of water detention grows,and the delay time of runoff also extends;while when rainfall intensity increases,the delay time of runoff shortens.As for different substrates,the maximum water content of substrates of large total porosity is large correspondingly;and the water retention capacity is related with the coefficient of non-uniformity of substrate particles,which means that more even particles lead to lower water retention capacity.%绿化屋顶基质层吸水饱和时的蓄水含量定义为最大含水量,最大含水量是绿化屋顶雨水滞蓄效果的重要评价指标.选择陶粒、草炭、煤渣等按不同组合不同配比设计6组基质配制方案,通过人工模拟降雨试验,探究了不同基质厚度、降雨强度及基质类型对屋顶绿化基质雨水滞蓄效果的影响.结果表明:对于同种屋顶绿化基质层,厚度、降雨强度不影响其最大含水量,但厚度越大,蓄水总量越大,延迟产流时间越长,而降雨强度越大,延迟产流时间越短;对于不同种绿化基质层,总孔隙度较大的基质组其最大含水量也相对较大,但基质层持水性与颗粒不均匀系数有关,颗粒越均匀,其持水性能越低.